Blower unit for oil burners



Oct. 23, 1956 w. F. CREED 2,767,905

BLOWER UNIT FOR OIL BURNERS Filed June 25, 1952 2 Sheefs-Sheet lINVENTOR WILLIAM E CREED BY v a ATTORNEYS 7 W. F. CRE ED BLOWER UNIT FOROIL BURNERS Oct. 23, 1956 2 Sheets-Sheet 2 Filed J1me 23, 1952 WILLIAMF: CREED form of the invention,-

Figure, 9 vis an innenend view of; the umt'shown 1nof Figure 8, q

native formiof theinventiom-and United States Patent() This inventionrelates to improvements in blower-units for oil burners.

Thisblower unitis particularly designed for oil burners in cookingstoves, but it may be used with burners for any other desired purpose.

The blower unit supplies airt'oa burner in varying degrees dependingupon the amount of oil being supplied thereto. When the burner is fullon, the full output of a draft fan is supplied to it. As the burner isturned down, the quantity of air is reduced accordingly. It is possibleto have theburnergoing with only a pilot light with the fan turned off.5

- The burner -unit comprises a housing having a fan rotatablymountedtherein, a main air inlet in the housing, and-an air outlet fromsaid' housing. A second air inlet is' provided in the housing throughwhich air from the outlet may return to the housing. Control means forthe outlet and the second inlet-is included by means'of which the,outlet isclosed as the inlet is opened and vice versa. -It 'is desirable to have the main inlet and second inlet opposedtoeach-other onopposite sides of 'the housing. The unit so constructed that 'When thefan is operating, it always draws air through the main 'air'inletregardless of the degree of'opening'or closing of the outlet and thesecond air inlet/ What'actually happens is that when'the burner requiresless air, some of the 'air from the fanis recirculatedby it. However,

as the fan always draws airfrom theoutside, there is no danger ofcombustion gases or oil fumes being discharged outside the heatingdevice. An important ad- I vantage of this unit lies in the fact that ifthemotor which drives the fan fails or the electric power is "cut off,the

burner still operates withnatural draft."

Examples of this inventiona're illustrated in the ac-.companyingfdrawings, in which:

Figure 1 is an'elevation of a heatingdevicgeppartly stalled therein, V

Figure 2 is an enlarged plan view ofthe blower unit,

shown partly in section,

Figure 6 is a cross section taken on the line 6 6 of Figure 4 with theair inlets full open, v I I 9 Figure 7 is a view similar to. Figure 6with-the air inlets half open,

Figure 8 isa view Figure 8, v e

Figure 10 is a vertical section taken on the line 10-10 Figure 11 is aview-similar. to Figure-4 of .ahother-altersect1on, w1th.an o1l burnermeludrng a blower unlt 1n-' 2,767,905 Patented Oct. 23, 1956 Figure 12is an inside end view of the unit of Figure 11.

Referring to Figure 1 of the drawings, 10 is a heating device, such as acooking stove, having a combustion chamber 11 therein from which a flue12 extends. An oil burner unit 13 is installed in the combustionchamber. This unit consists of a closed casing 15 mounted on a wall 16of the heatingdevice. Thiscasing has a large hole 17 at one end'thereofregistering with a similar hole 18 in'the burner wall 16. Aipotoilburner 20 is mounted in and opens outwardlyv through the top of thecasing 15. This burner has the usual holes 21 in the wall thereofthrough which air passes to aidcombustion in the pot. If desired, abaffle 22 may lie between the pot burner and the casing hole 17, saidbaflie having a hole .23 beneath the bottom of the pot through which airfrom the casing may pass. Oil is supplied to the bottom burner from asuitable source, not shown, by a pipe 24.

Figures 1 to 7 illustrate a blower unit 28 mounted on the outer surfaceof the heater wall 16 over the hole 18 thereof. This unit comprises ahousing 32 having a fan 33 mounted therein centrally thereof. This fanis preferably a centrifugal fan having a plurality of blades '34projecting outwardly from a central hub 35. The

fan includes an electric motor 37 having a shaft 38 ex tending into thehousing centrally thereof upon which the hub 35 is fixedly mounted. Themotor is mounted on and spaced'from the outer wall 39 of thehousing bymeans of 'a plurality of brackets 40. The housing has an inner wall "44:having an annular ring 45 projecting inwardly thereof which partiallyoverlaps the fan blades .34,. said blades terminating just clear of thering, see

Figure 4. The fan is smaller in diameter than the housing .32-so that apressure chamber 47 is formed within the housing around the fan.

opposite the main inlet 50. 'In this ex ample,.there are a plurality ofthese second inlets radiating from the centre of the wall. By referringto Figure 6, it will be noted that there is one opening 54 for and inline with each outlet 51. It is.desira ble that the combined area oftheseinlet openings be substantially the same as the combined area ofthe outlet openings.

The openings 54 are radially arranged with their outer ends 55 farther.from the axis ofrotation of the fan than the outer edge 56 of 'themaininlet. The combined area of the second inlets 54 is substantially equalto that of the main inlet 50. 7

Suitable control means is provided for opening the outlets 51 while thesecond inlets 54 are being closed, and

'vice versa. This may be done by means of a control plate 50 rotatablymounted on the inner housing wall 44 by means of a stud 61. The centreof rotation of this similar to Figure 4 of an alternative platecoincides with the longitudinal axis of the fan 33. Thisplate has anouter opening 64for each outlet 51 of .the housing. Each outer openingis the same size and shape as its outlet opening, and when the controlplate isrotated, the former is moved into and out of registry with thelatter. The control plate is also formed with an inner opening 66 foreach of' the second inlets 54 of the housing. The inner openings are thesame size and shape as these housing inlets, and when the control plateis rotated, the inner openings thereof-are moved into and out ofregistry with the'inlets. By. referring'to Figure 5,

and forth in any desiredmanner.

it will be noted that the plate openings 64 are staggered in rclationtothe openings 66. With this arrangement, the outer openings move intoregistry with the housing outlets while the inner plate openings moveout of registry with the housing second inlets, and vice versa.

The control plate60 is rotated in any convenient manner. This may bedoneby means of apin70 which is connected to the plate adjacent itsperiphery and extends outwardly through an arcuate slot 71 formed inapart of the inner wall 44 which projects beyond the peripheral wallof-the housing 32. A link 72 connects this pin to the upper endof thelever 73 which-ispivotally mounted at its lower end at '74. This levermay be pivoted back For example, a link 76 may extend=from the leverinto a carburetor 77'for the pot burner 20. This carburetor has theusual oil control knob 78, and suitable means not shown, is-providedwithin the carburetor for connecting the link 76 to this -knob so thatwhen the latter is turned to increase the flow of oil to the pot burner,lever 73-is moved in one direction, and when the knob is turned toreducethe flow .of .oil,.the lever is moved in-the opposite direction. Thismovement. of the lever rotates the control plate.

Assumingthat the burner unit is operating with a meflarne, the controlplate 60 is set so'that'both the :atr outlets 51 and second air inlets54 of the housing 32 are approximately half open. The fan 33- blows airthrouglrthe openings 51 and 64 into the casing 15 of' the oil burnerunit. The fan alwaysturns at the .same speed.

The amount of air blown into the burner unit casing is reduced owing tothe fact that the outlets 51 are only half open. At thesarne time, thefandraws air through the main inlet 50 and through the second inlets 54.This keeps the pressure of the air, in ,the casing 15 downso that thepot 20 receives only sufficient air for proper combustion. As the inlets54 are only half open at this time, the fan will draw more air throughthe fully open main inlet so that there is no dangerof combustiongasesor oil fumes being discharged into the atmosphere outside theheating device through the blower unit.

When the control plate is. moved fully to open theoutlets 51, theinlets54 are closed. This results in the full output of the fan beingdirected" into the casing 15. This action takes place-when the oil isfully turnedonh When the oil is turned almost to i lowest point, thecontrol plate is rotated to close the outlets 51 and fully open theinlets 54. At this time, most of the draft for I the pot is naturalsince the suction of the flue 12 creates an area of low pressure in.thecasing 13. H oweveg the outer ends 55 of the inlets 54 are positionedfarther from the axis of rotation of the fan than the outer edge 56 ofthe, main inlet. As a result of this, the centrifugal action of thefanwill direct a small amount of air into the casing through the secondinlet openings. 1

When only sufficient oil is supplied to the burner to maintain a pilotlight, the fan may be turned off, at which time air is free to movethrough the main inlet, the fan, and the second inlets into the casing.This takes place when themotor 37 or the electrical current i'ails. Thislatter feature is very important since the failure may take place whenconsiderable oil is being directed to the pot. If no draft wasavailable, the pot would soon carbon up, and the interior wallsof thecombustion chamber 11 of the heating device and of the flue 12 wouldsoon be covcred with soot.

Figures 8 to illustrate an alternative form of the invention, in whichthe housing 32 is provided with an inner wall 84. This inner wall hasspaced inner and outer annular flanges 8S and 86 projecting inwardlytherefrom into the housing, the inner edges of said flanges beingconnected by a wall 87. Thus, wall 84, flanges 85 and 86, and wall 87actually form the inner wall of the housing, flange 85 defining anopening in this wall communicating with the fan centre. A control plate90 is rotatably supported by the inner wall of the housing, and has 4spaced inner and outer annular sleeves 91 and 92 slida- .blyfittingwithinthe inner and outer flanges, respectively.

A plurality of openings are formed in both flanges and both sleeves. Theflanges and 86 are formed with second inlet openings 94 and outletopenings 95, and the sleeves 91 and 92 are formed with second inletopenings 96 and outlet openings 97. These are arranged so that thesleeve openings 97 register with the flange openings 95 when the sleeveopenings 96 are completely out of registry with the flange openings 94,and vice versa. The second inlet openings communicate with the centre ofthe fan through sleeve 91 fitting within flange 85. The control plate isformed with a plurality of holes 100 between the sleeves thereof.

A sealing ring 104extends inwardly from the wall 87 to the blades of thefan 33 adjacent the outer end thereof to prevent air from moving fromthe pressure chamber 47 towards the inner sleeve 91. Suitable means ispro vided forrotating the control plate 90. This may be done by a rod106 which is pivotally connected at one end to the plate and extendsoutwardly from the unit. The blower unit ofcFigurcs 8 to 10 functions inthe same manner as the one shown in.Figurcs 1 to 7. The control platemay be rotated to bring the openings 97 into complete. registry with theopenings 95, at which time the openings 94 are. completclyrout ofregistry with openings 96. This. setting, is shown in Figures 8 and. 10.The full force of air from the fan is directed through the outletopenings and plate openings into the burner unit casing 15. The controlplate may be rotated gradually to close the outlet openings and to openthe inlet openings, As the latter openings are uncovered, some of theair from the casing 15 is drawn into the housing 32 by the fan forrecirculation. When the outlet openings are completely closed, thesecond inlet openings are full open, at which time air may be drawn into'and. a centrally located second inlet opening 112. A

sleeve surrounds the opening 112 and projects outwardly from the wall110. A control plate 118 having a central hub 119 projecting outwardlytherefrom is rotatably mounted on the sleeve. Thecontrol plate and itshub are movable back and forth on the sleeve, and this can beaccomplished in any convenient manner. For example, a pin .122 mayproject inwardly from the hub through an angularly-arranged slot 123 inthesleeve 112. When the plate is rotated on the sleeve, the pin 122forces it to move back and forthon said sleeve. A rod 125 may beconnected todhe plate adjacent the periphery thereof for rotating saidplate.

A cover 127 is supported in line with the outer end of the hub 119..This cover may be supported ,by a plurality of arms 128'extendingtherefrom to the inner wall 110 beyond the periphery of. the controlplate. The control plate 118, overlaps and closes the outletslll when itbears against the inner wall 110. When the control plate is moved awayfrom said wall by the rotation thereof, the hub 119 moves intoengagement with the cover 127 so that air cannot enter the blowerhousing 32 through said hub. When the control plate is in the latterposition, the outlets 111 are full open, and the inlet opening 112 iscompletely closed as the'hub is in engagement with the cover. When thecontrol plate is rotated in the opposite direction, the inlet opening isuncovered and the outlet openings are covered. A sealing ring 129extends inwardly from the wall ll0to thefan blades adjacent the outerends thereof.

What I claim as my invention is:

1. A blower unit for oil burners and the like comprishousing, a main airinlet in the housing for directing air to the centre of the fan, anair:outletfrom the housing adjacent the outer edge of the fan, a secondair inlet in the housing on the side of .the fan remote from the maininlet and communicating withthefan centre and through which air from theoutlet may return to the housing, said fan being, capable of drawing airthrough both inlets and discharging it near the outlet, and controlmeans at the outlet and the second inlet for opening and closing same,said control means opening the outlet when closing the inlet and openingthe latter when closing the former. W 2. A blower unit-"as claimed-inclaim 1 inwhich the i'area of the'second inletwhen it iscompletelyopen-is no greater than thatotthe maininlet. s -3. A-'blowerunitfor, oil burners and'the like compris- ,ing:a housing, a fanrotatably mounted in the housing and having an air inlet and outlet, amain air inlet in the housing, an air outlet from the housingcommunicating with the fan outlet, a second air inlet in the housingthrough which air from the outlet may return to the housing, said mainand second air inlets communicating with the fan inlet, and a controlplate at and for opening and closing the outlet and the second inlet,said plate being movable to one position opening the outlet and closingthe inlet and to another position opening the latter and closing theformer.

4. A blower unit for oil burners and the like comprising a housing, afan having radiating blades rotatably mounted in the housing, amaininlet opening in a wall of the housing at the centre of rotation ofthe fan, a second inlet opening in a housing wall substantially in linewith the main opening on the opposite side of the fan and communicatingwith the fan centre, an outlet opening in the same housing wall as thesecond inlet opening spaced outwardly from the latter in a radialdirection, said fan being capable of drawing air through both inletopenings and directing it to the outlet opening, and control means forclosing and opening the second inlet oening and respectively opening andclosing the outlet opening at the same time.

5. A blower unit for oil burners and the like comprising a housing, acentrifugal fan rotatably mounted in the housing centrally thereof, saidhousing having outer and inner ,walls on opposite sides of the fan, amain air inlet in the centre of the outer wall and communicating withthe fan centre, an air outlet in the inner wall adjacent the outer edgeof the fan, a second air inlet centrally of the inner wall communicatingwith the centre of the fan and through which air from the outlet mayreturn to the housing, a control plate movably mounted on the innerwall, an outer opening in the plate adjacent the housing outlet, and aninner opening in the plate adjacent the second inlet, the outer plateopening being moved into registry with the outlet as the inner openingis moved out of registry with the second inlet and vice versa.

6. A blower unit for oil burners and the like comprlsing a housing, 'acentrifugal fan rotatably mounted in the housing centrally thereof, saidhousing having outer and inner walls on opposite sides of the fan, amain air inlet in the centre of the outer wall and communicating withthe fan centre, a plurality of spaced air outlets in the inner wallarranged around the outer edge of the fan, a plurality of spaced secondair inlets arranged around the centre of the inner wall communicatingwith the centre of the fan and through which air from the outlet mayreturn to the housing, a control plate movably mounted on the innerwall, an outer opening in the plate adjacent each housing outlet, and aninner opening in the plate adjacent each second inlet, the outer plateopenings being so positioned relative to the inner plate openings thatwhen the former are moved into registry with the outlets the inneropenings are moved out of registry with the second inlets and viceversa.

7. A blower unit as claimed in claim 6 including means between the outeredge of the fan and the second inlets 6 for normally preventing air fromthe fan from passing out of the housing through the second inlets. U

8. A blower unit as claimed in claim 6 in which the total area of thesecond inlets when uncovered is no greater than that of the main inlet.i i i 9. A blower unit as claimed in claim 6 in whichthe secondinlets-are radially arranged with their outer ends positioned fartherfrom the axis of rotation of the 'fan than the outer edge of the maininlet.

10. A blower unit for oil burners and the like comprising a housing, acentrifugal fan rotatably mounted in the housing centrallythereof, saidhousing having outer and inner w alls on opposite sides of the fan, amain air inlet in the centre of the outer wall and communicating 'withthe fan centre, spaced inner and outer annular flanges projecting intothe housing from the inner-wall thereof, a control plate rotatablymounted on the inner wall centrally thereof, spaced inner and outerannular sleeves on the plate slidably fitting respectively within theinner and outer flanges, inlet and outlet openings in the inner andouter flanges, corresponding openings in both sleeves, the openings ofthe inner sleeve registering with the openings of the inner flange whilethe openings of the outer sleeve are completely out of registry withthose of the outer flange and vice versa, the openings of the innerflange and sleeve communicating with the centre of the fan, a wallclosing otf the space between the flanges from the interior of thehousing, and means for rotating the control plate to change the settingof the openings in the sleeves thereof relative to the openings of theflanges.

11. A blower unit as claimed in claim 10 in which the wall closing offthe space between the flanges and the interior of the housing isconnected to the inner edges of said flanges, and including a sealingring extending inwardly from said wall to the fan adjacent the peripherythereof, and a plurality of holes in the control plate between thesleeves thereof.

12. A blower unit for oil burners and the like comprising a housing, acentrifugal fan rotatably mounted in the housing centrally thereof, saidhousing having outer and inner walls on opposite sides of the fan, amain air inlet in the centre of the outer wall and communicating withthe fan centre, an air outlet in the inner wall adjacent the outer edgeof the fan, a second air inlet centrally of the inner wall communicatingwith the centre of the fan andthrough which air from the outlet mayreturn to the housing, a sleeve around the second inlet projecting fromthe inner wall outwardly of the housing, a control plate having acentral hub projecting outwardly therefrom rotatably mounted on thesleeve, a cover supported in line with the outer end of the hub spacedtherefrom when the control plate bears against the adjacent housingwall, said plate overlapping the air outlet in the inner housing wall,and means for moving the control plate back and forth on the sleeve, theouter end of the hub being closed by the cover when the plate is movedoutwardly and the air outlet being covered by the plate when the latteris moved inwardly. v

13. A blower unit for oil burners and the like comprising a housing, acentrifugal fan rotatably mounted in the housing centrally thereof, saidhousing having outer and inner walls on opposite sides of the fan, amain air inlet in the centre of the outer wall and communicating withthe fan centre, a plurality of spaced air outlets in the inner wallarranged around the outer edge of the fan, a second air inlet centrallyof the inner wall communicating with the centre of the fan and throughwhich air from the outlet may return to the housing, a sleeve around thesecond inlet projecting from the inner wall outwardly of the housing, acontrol plate having a central hub projecting outwardly therefromrotatably mounted on the sleeve, a cover supported in line with theouter end of the hub spaced therefrom when the control plate bearsagainst the adjacent housing wall, said plate overlapping the outlets inthe inner housing wall, means for rotating the con- 7 trol plate on thesleeve, and means for moving the plate back and forth on the sleeve whenit is rotated, the outer end of the hub being closed by the cover whenthe plate is moved outwardlyand the air outlets being covered by theplate when the latter is moved inwardly.

14. A blower unit for oil burners and the like comprising a housing, acentrifugal fan rotatably mounted in the housing, a main air inlet inthe housing for directing air to the centre of the fan, an air outletfrom the housing adjacent the outer edge of the fan, a second air inletinthe housing on the side of the fan remote from the main inlet andcommunicating with the centre of the fan and'through which air from theoutlet may return to the housing, said fan being capable of drawing airthrough both inlets and discharging it near the outlet, control means atthe outlet and the second inlet for opening and closing same, saidcontrol means opening the outlet when closing the inlet and opening thelatter when closing the former, and means connected to the control meansfor operating the latter tolset the degree-of opening and closing of theoutlet and secondinlet relative towaeh other-at any desired-point.

RcferencesiCitedin the file of this patent UNITEDSTATES PATENTS

